Thin film processing method and thin processing apparatus

Abstract

A thin film processing method for processing the thin film by irradiating an optical beam to the thin film. A unit of the irradiation of the optical beam includes a first and a second optical pulse irradiation to the thin film, and the unit of the irradiation is carried out repeatedly to process the thin film. The first and the second optical pulse have pulse waveforms different from each other. Preferably, a unit of the irradiation of the optical beam includes the a first optical pulse irradiated to the thin film and a second optical pulse irradiated to the thin film starting substantially simultaneous with the first optical pulse irradiation. In this case, the relationship between the first and the second optical pulse satisfies (the pulse width of the first optical pulse)<(the optical pulse of the second optical pulse) and (the irradiation intensity of the first optical pulse)≧(the irradiation intensity of the second optical pulse). A silicon thin film with a small trap state density can be formed by the optical irradiation.

1. A thin film processing apparatus for processing a thin film by irradiating an optical beam onto the thin film, comprising:
 first and second pulse optical sources for producing first and second optical pulses which have pulse waveforms different to each other, 
 wherein one unit of irradiation of the optical beam includes irradiations due to the first and second optical pulses onto the thin film, and 
 the thin film is processed by repeating the one unit of irradiation, 
 wherein the first and second optical pulses control a cooling rate to 1.6×10 10 ° C./sec or less, which prevents the thin film from becoming microcrystalline or amorphous while growing the crystal size of the thin film. 
 
   
   
     2. A thin film processing apparatus as claimed in  claim 1 , wherein:
 the one unit of irradiation includes the first optical pulse irradiation to the thin film and the second optical pulse irradiation to the thin film which substantially starts simultaneously with the irradiation of the first optical pulse. 
 
   
   
     3. A thin film processing apparatus as claimed in  claim 2 , wherein:
 a relationship between the first and the second optical pulse satisfies that a pulse width of the first optical pulse is smaller than a pulse width of the second optical pulse and an irradiation intensity of the first optical pulse is not lower than an irradiation intensity of the second optical pulse. 
 
   
   
     4. A thin film processing apparatus as claimed in  claim 1 , wherein:
 the one unit of irradiation includes the first optical pulse irradiation to the thin film and the second optical pulse irradiation to the thin film which substantially starts with a delay to the first optical pulse irradiation. 
 
   
   
     5. A thin film processing apparatus as claimed in  claim 4 , wherein
 a relationship between the first and the second optical pulse satisfies (a pulse width of the first optical pulse)<(a pulse width of the second optical pulse). 
 
   
   
     6. A thin film processing apparatus as claimed in  claim 5 , wherein
 the relationship between the first and the second optical pulse satisfies (the irradiation intensity of the first optical pulse)≧(the irradiation intensity of the second optical pulse).